zypp/ProblemSolution.h

   1 /**
   2  *
   3  * Easy-to use interface to the ZYPP dependency resolver
   4  *
   5  * Author: Stefan Hundhammer <sh@suse.de>
   6  *
   7  **/
   8
   9 #ifndef ZYPP_PROBLEMSOLUTION_H
  10 #define ZYPP_PROBLEMSOLUTION_H
  11
  12 #include <list>
  13 #include <string>
  14
  15 #include "zypp/base/ReferenceCounted.h"
  16 #include "zypp/base/PtrTypes.h"
  17 #include "zypp/Resolver.h"
  18 #include "zypp/solver/detail/Resolver.h"
  19 #include "zypp/ResolverProblem.h"
  20 #include "zypp/solver/detail/SolutionAction.h"
  21 #include "zypp/solver/detail/Types.h"
  22
  23 /////////////////////////////////////////////////////////////////////////
  24 namespace zypp
  25 { ///////////////////////////////////////////////////////////////////////
  26
  27
  28     /**
  29      * Class representing one possible solution to one problem found during resolving
  30      *
  31      * All problems should have at least 2-3 (mutually exclusive) solutions:
  32      *
  33      *    -      Undo: Do not perform the offending transaction
  34      *   (do not install the package that had unsatisfied requirements,
  35      *    do not remove  the package that would break other packages' requirements)
  36      *
  37      *    - Remove referrers: Remove all packages that would break because
  38      *  they depend on the package that is requested to be removed
  39      *
  40      *    - Ignore: Inject artificial "provides" for a missing requirement
  41      *  (pretend that requirement is satisfied)
  42      **/
  43     class ProblemSolution : public base::ReferenceCounted
  44     {
  45     protected:
  46
  47         /**
  48          * Clear all data.
  49          * In particular, delete all members of _actions.
  50          **/
  51         void clear();
  52
  53         //
  54         // Data members
  55         //
  56         ResolverProblem_Ptr     _problem;
  57         solver::detail::CSolutionActionList     _actions;
  58         std::string             _description;
  59         std::string             _details;
  60
  61     public:
  62
  63         /**
  64          * Constructor.
  65          **/
  66         ProblemSolution( ResolverProblem_Ptr parent, const  std::string & description, const std::string & details );
  67
  68         /**
  69          * Destructor.
  70          **/
  71         ~ProblemSolution();
  72
  73         // ---------------------------------- I/O
  74
  75         friend std::ostream& operator<<(std::ostream&, const ProblemSolution & solution);
  76         friend std::ostream& operator<<(std::ostream&, const ProblemSolutionList & solutionlist);
  77         friend std::ostream& operator<<(std::ostream&, const CProblemSolutionList & solutionlist);
  78
  79         // ---------------------------------- accessors
  80         /**
  81          * Return a one-line text description of this solution.
  82          **/
  83         std::string description() const { return _description; }
  84
  85         /**
  86          * Return a (possibly multi-line) detailed description of this
  87          * solution or an empty string if there are no useful details.
  88          **/
  89         std::string details() const { return _details; }
  90
  91         /**
  92          * Return the parent dependency problem.
  93          **/
  94         ResolverProblem_Ptr problem() const { return _problem; }
  95
  96         // ---------------------------------- methods
  97
  98         /**
  99          * Apply this solution, i.e. execute all of its actions.
 100          *
 101          * Returns 'true' on success, 'false' if actions could not be performed.
 102          **/
 103         bool apply (solver::detail::Resolver & resolver);
 104
 105         /**
 106          * Add an action to the actions list.
 107          **/
 108         void addAction( solver::detail::SolutionAction_constPtr action );
 109
 110     };
 111
 112
 113     ///////////////////////////////////////////////////////////////////////
 114 };// namespace zypp
 115 /////////////////////////////////////////////////////////////////////////
 116
 117 #endif // ZYPP_PROBLEMSOLUTION_H
 118